Fix and reapply IR PGO support for Flang (#142892)

This PR resubmits the changes from #136098, which was previously
reverted due to a build failure during the linking stage:

```
undefined reference to `llvm::DebugInfoCorrelate'  
undefined reference to `llvm::ProfileCorrelate'
```

The root cause was that `llvm/lib/Frontend/Driver/CodeGenOptions.cpp`
references symbols from the `Instrumentation` component, but the
`LINK_COMPONENTS` in the `llvm/lib/Frontend/CMakeLists.txt` for
`LLVMFrontendDriver` did not include it. As a result, linking failed in
configurations where these components were not transitively linked.

### Fix:

This updated patch explicitly adds `Instrumentation` to
`LINK_COMPONENTS` in the relevant `llvm/lib/Frontend/CMakeLists.txt`
file to ensure the required symbols are properly resolved.

---------

Co-authored-by: ict-ql <168183727+ict-ql@users.noreply.github.com>
Co-authored-by: Chyaka <52224511+liliumshade@users.noreply.github.com>
Co-authored-by: Tarun Prabhu <tarunprabhu@gmail.com>

1 files changed, 10 insertions, 0 deletions

diff --git a/flang/lib/Frontend/CompilerInvocation.cpp b/flang/lib/Frontend/CompilerInvocation.cpp
index 15bcff2..147849b 100644
--- a/flang/lib/Frontend/CompilerInvocation.cpp
+++ b/flang/lib/Frontend/CompilerInvocation.cpp
@@ -29,6 +29,7 @@
 #include "llvm/ADT/StringRef.h"
 #include "llvm/ADT/StringSwitch.h"
 #include "llvm/Frontend/Debug/Options.h"
+#include "llvm/Frontend/Driver/CodeGenOptions.h"
 #include "llvm/Option/Arg.h"
 #include "llvm/Option/ArgList.h"
 #include "llvm/Option/OptTable.h"
@@ -441,6 +442,15 @@ static void parseCodeGenArgs(Fortran::frontend::CodeGenOptions &opts,
       opts.IsPIE = 1;
   }
 
+  if (args.hasArg(clang::driver::options::OPT_fprofile_generate)) {
+    opts.setProfileInstr(llvm::driver::ProfileInstrKind::ProfileIRInstr);
+  }
+
+  if (auto A = args.getLastArg(clang::driver::options::OPT_fprofile_use_EQ)) {
+    opts.setProfileUse(llvm::driver::ProfileInstrKind::ProfileIRInstr);
+    opts.ProfileInstrumentUsePath = A->getValue();
+  }
+
   // -mcmodel option.
   if (const llvm::opt::Arg *a =
           args.getLastArg(clang::driver::options::OPT_mcmodel_EQ)) {